# ReadDiscrete

Reads a range of bits from a discrete input channel.

## ReadDiscrete Inputs

Parameter | Description
Event | Specifies the update event on which to read. This parameter must be a reference to one of the following: The Image data structure in cell A0, containing the AcquireImage function. A cell containing an Event function. A cell containing a Button function.
Start Bit | Specifies the first bit of the set to be read. CC24 Cognex Communication Card: 0 to 7; default = 0 In-Sight D900 Series Vision System: 1 to 2; default = 1
Number of Bits | Specifies the number of bits in the set to be read. CC24 Cognex Communication Card: 1 to 8; default = 1 In-Sight D900 Series Vision System: 1 to 3; default = 1

## ReadDiscrete Outputs

Returns | The positive integer value read, or #ERR for any invalid input parameter.